Organo-montmorillonite (OMMT) was treated with 3-amino-propyltrimethoxysilane. Epoxy (E) composites reinforced with glass fibber (GF) and OMMT were prepared with the hand-lay up technique. The flexural properties of the E/GF/OMMT composites were characterised by the three-point bending flexural test. The flexural modulus and strength of the E/GF composites were improved by the addition of silane-treated OMMT. The exfoliation of the OMMT in the E was studied using X-ray diffraction (XRD). It was found that the OMMT silicate layers were exfoliated successfully in the E matrix. The flexural fractured surface morphology of the E/GF/OMMT composites was investigated using scanning electron microscopy (SEM). It is interesting to note that parts of the silane-treated OMMT also adhered to the GF, which can promote better interfacial interaction and wettability between the E and GF.